Three-speed bicycle gearshift



Dec. 2, 1947. M. A. BARNETT ,2,431,982

THREE SPEED BICYCLE GEAR SHIFT Filed May 1e, 1946 2 sheets-sheer 1 MILToN BARNETT.

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Dec. 2, 1947. M. A. BARNETT THREE SIPEED BICYCLE GEAR SHIFT Filed May 16, 1946 2.Sheets-Sheet 2 m mi,

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Patented Dec. 2, 1947 TED mines torri- CE 2,431,982 THRESPEBICYCELGEKSHIFT .sMilt'onlA...Brnett,StsiEcmispMoi 'npplicaffbnflmayin 1946,.;serisLNo. 676,251

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.Thisdriverition relates to ya-threespeed1lbicfycle gear ft 'object of "the 'invention is the construction within a gear housing or casing of a mechanism including a plurality of gearsrarranged in a horizei-ital; condition, and capable `fof. -bei-n'g shift-'ed in a horizontal plane.

Another object of the Vinventionis the construction oian e'i'cient'and durable'ge'ar mechanism employed in the construction of a bicycle',- Whereby the'driving orpropulsi'on of tliielbi'cy'cle is easily accomplished with `relatively :a .small amount of exertion by Vthe rider'.

WithV the foregoing and other objects in view, my invention comprises certain novel constructions, combinations, and arrangements of parts as will be hereinafter fully described, illustrated in the accompanying drawings, and more partic ularly pointed out in the appended claims.

In the drawings:

Figure 1 is a horizontal longitudinal sectional View of a housing or casing and mechanism constructed in accordance with the present invention.

Figure 2 is a vertical longitudinal sectional view through the housing or casing showing in dotted lines the position of the gears within the casing.

Figure 3 is a transverse sectional view taken on line 3-3 of Fig. 1, and looking in the direction of the arrows.

Referring to the drawings in which I have shown the preferred embodiment of my invention, I designates an elongated housing or casing which is suitably supported upon the bicycle frame 2. Ext-ending transversely of the casing I is a drive shaft 3, and a pedal shaft 4. These shafts are mounted in suitable ball-bearings 5. Pedals 6 are xedly secured to the pedal shaft 4 outside of casing I.

On the drive shaft 3 is iixedly secured the low speed driven gear 'I, the standard speed driven gear 8, and the high speed driven gear 9. On the pedal shaft 4 is fixedly secured the low speed driving gear 1a, the standard speed drive gear 8E, and the high speed drive gear 9a.

It is to be understood that the shafts 3 and 4 are in the same horizontal plane so that the entire mechanism is in substantially the same horizontal plane.

Between the sides of the elongated casing I are plate-like vertical supports I and I I. A side stub shaft I2 is mounted at its outer end upon the casing I and at its inner end upon the plate-like vertical support I0. Intermediate stub shaft I3 rfa-sone"end-monntedfupon'plateflikesupport 10' and its'retirerentiisinountecrupon;plateilikesup-Y port Ff. "i'de stbifshaft' F4 v-l'iasfits' 'outer 'end flifedl'y -mounte'- upon `t'h-e 'si'deof easing 3II and iftsiinnerfendfisnxedly'mounted"upon tlreplate; llkesuppnrt H. "Therefore itswillbe-fseen upon referring -td Figure r that-the supports f I u Aand fl as lWellasf-shafts J'I-2, 13', land -I-4 A arei arranged/out of al'igmnent transversely'of 'casing AI', f'or Ieffi` ciexitly supporting fthe idle Lgears hereinafter described.

v -'A hig'nspeedidlegear `ft ismounted upon side stub-"shaft I2, yand is adapted 't'o'tmesh"with "gears 9' randA 3"1. A 4vstamdard 'speed idler gear' I6 :is mounted upon intermediatestub shaft I3, and as shown in Fig. l this gear meshes with gears 8 and 8a. Low speed idle gear II is loosely mounted upon stub shaft I 4, and is adapted to mesh with gears I and 18. Each idle gear I5, I6, and I'I is provided with a grooved bracket engaging flange I8.

Suitable manually controlled operating means may be provided for operating or shifting in and out of mesh the idle gears I5, I6, and I'I. For instance, as shown in dotted lines Fig. 2, a gear shift lever I9 may be employed together with a forked bracket 20, these two elements being con'- nected by gear shift shaft 2 I. The fork of bracket 20 is seated in the grooved bracket engaging ange I8, so as to adjust the idle gear as the operator desires.

The casing I is preferably provided with a removable side Ia; the casing and its side, as well as the mechanism within the casing are retained in their assembled position by transverse bolts 22.

In my mechanism I have invented a very compact gear arrangement in a horizontal plane, which enables the mechanism to be placed upon a bicycle in a relatively small space, and by reason of the peculiar arrangement highly satisfactory results are obtained in operating a bicycle equipped with this mechanism.

While I have described the preferred embodiment of my invention and illustrated the same in the accompanying drawings, certain minor changes or alterations may appear to one skilled in the art to which this invention relates during the extensive manufacture of the same, and I, therefore, reserve the right to make such changes or alterations as shall fairly fall within the scope of the appended claims.

On the drive shaft 3 is sprocket wheel 3a. The sprocket wheel is rotated in the usual manner, 'to impart rotary movement to the wheels, when the bicycle is being used.

The vertical plate-like supports l and Il are integral with the horizontal base lla, and said base is secured upon the bottom of casing l by screws IIb.

What I claim is:

1. In a mechanism of the class described, the combination with a casing, of a drive shaft in said casing, a pedal shaft in said casing in the same horizontal plane with said drive shaft, three gears xedly secured upon said drive shaft, three gears xedly secured upon said pedal shaft,

three stub shafts between and in the same hori-vA zontal plane with said drive and pedal shafts,

means supporting said stub shafts upon said casing, and idle gears on said stub shafts and being adapted to mesh with their corresponding pedal shaft gears and drive shaft gears.

2. In a mechanism of the class described, the combination with an elongated casing, of a drive shaft extending transversely of said casing, a

pedal shaft extending transverselyl of said casing and in the same horizontal plane-with said drive shaft, three gears fixedly secured upon said drive shaft, three gears iixedly secured upon said pedal shaft, stub shafts between and in the same horizontal plane with said drive and pedal shaft, means supporting said stub shafts out of transverse alignment upon said casing, and idle gears on said stub shafts and being adapted to mesh with their corresponding pedal shaft gears and drive shaft gears.

3. In a mechanism of the class described, the combination with an elongated casing, of a drive shaft extending transversely of said casing, ballbearing devices supporting said drive shaft upon said casing, a pedal shaft extending transversely of said casing, ball-bearing devices supporting said pedal shaft upon said casing, said drive and pedal shafts being in horizontal alignment, a pair of vertical plate supports upon said casing and positioned near its center and between its sides, gears Xedly secured to said drive shaft. gears Xedly secured to said pedal shaft, said vertical plate supports being arranged in staggered position transversely of said casing, side stub shafts having their outer ends fixedly mounted on the sides of said casing and their REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date '702,930 Dicks June 24, 1902 12,061,225 Duvall Nov. 17, 1936 2,210,221 Sperry! Aug. 6, 1940 

